Obese kids’ tastebuds less sensitive, study finds

By Jennifer LaRue HugetBy Jennifer LaRue HugetSeptember 19, 2012

Children and adolescents who are obese may have less-sensitive taste buds than kids of normal weight do, new research finds.

In a study conducted in Germany and published Wednesday evening in the BMJ’s Archives of Disease in Childhood, simple taste tests were administered to 99 obese kids and 94 kids of normal weight. Each of the young people, who ranged in age from 6 to 18, tasted 20 strips of paper that had been treated with varying concentrations of substances associated with the five known qualities of taste — sweet, sour, salty, bitter and umami – and to identify which of the five qualities the strip represented. A perfect score of 20 would have meant that the taster correctly identified each of the five qualities at all four levels of intensity.

By and large, the obese young people had more trouble discerning tastes than the others did: The average score among the obese youngsters was 12.6, compared to 14 among the normal-weight kids. (Individual scores ranged from 2 to 19.) The obese kids had particular trouble identifying salty, umami and bitter tastes.

That lack of sensitivity could help govern kids’ food choices, perhaps steering them away from more healthful foods that their palates perceive as less satisfying and prompting them to consume greater quantities of certain foods in order to achieve a desired taste sensation, the study suggests.

A second experiment focused just on sweet taste, with participants asked to distinguish varying levels of sweetness presented on test strips. Obese and normal-weight kids all did a good job of accurately ranking the levels of sweetness, but the obese kids tended to rate the levels of sweetness lower than the other kids did. Outside the lab, that might translate to a child’s requiring a more highly sweetened food to satisfy his or her sweet tooth – which could mean more calories and perhaps add up to more pounds.

Also, among kids of normal weight, the older participants were better able to identify tastes than the younger ones. But that was not the case among the obese children. The authors note, “A better taste differentiation with increasing age is thought to be the normal development. The absence of an increase of taste sensitivity in obese children and adolescents supports the hypothesis that the taste system is affected in obese subjects.”

Science has already established that different people experience taste in different ways, the study notes, though nobody has figured out why. Most likely it’s a combination of genetics, hormones, cultural influences and the extent to which a person is exposed to different taste sensations in early childhood that determines taste sensitivity.

Getting a better handle on this phenomenon could eventually lead to new approaches to combating childhood obesity, the study concludes. According to the CDC, more than one-third of U.S. children and teens are overweight or obese.